Dishwasher and control method thereof

ABSTRACT

A dishwasher includes: a tub defining a space that is configured to receive a target object to be washed, a sump disposed below the tub and configured to receive water, a pump connected to the sump and configured to move the water in the sump to the space of the tub, an air jet generator configured to receive a part of the water discharged from the pump and configured generate air bubbles in the water, and a control valve configured to control a flow of the water to the air jet generator.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0011653, filed on Jan. 27, 2021, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a dishwasher, and more particularly, to a dishwasher having an air jet generator for generating air bubbles.

BACKGROUND

A dishwasher is a household appliance that removes food particles remaining on dishes by spraying water on the dishes.

The dishwasher includes a tub having a space formed therein, and a sump mounted on the bottom of the tub to store water. The pump is configured to move the water stored in the sump to the inner space of the tub, where the pumped water washes dishes disposed in the inner space of the tub, and then flows into the sumpilters out after foreign substances are filtered out by a filter. The water circulates through the sump and the tub to wash dishes.

A conventional dishwasher includes an air jet generator that generates air bubbles in water supplied to a tub by using a part of water that is moved by a pump.

However, the air jet generator in the conventional dishwasher may generate noise caused by friction with water when air is sucked in. Such noise is generated during operation of the dishwasher and may provide discomfort to a user.

SUMMARY

The present disclosure is directed to a dishwasher capable of minimizing noise occurring during an operation of an air jet generator.

The present disclosure is also directed to a dishwasher that secures a flow rate of water supplied to an air jet generator.

According to one aspect of the subject matter described in this application, a dishwasher can include a tub defining a space that is configured to receive a target object to be washed, a sump disposed below the tub and configured to receive water, a pump connected to the sump and configured to move the water in the sump to the space of the tub, an air jet generator configured to receive a part of the water discharged from the pump and configured generate air bubbles in the water, and a control valve configured to control a flow of the water to the air jet generator.

Implementations according to this aspect can include one or more of the following features. For example, the pump can include a housing, a water inlet pipe that protrudes from a first side of a circumferential surface of the housing and that is connected to the sump, a water outlet pipe that protrudes from the first side of the circumferential surface of the housing and that is connected to a spray nozzle disposed inside the space, an impeller rotatably disposed inside the housing and configured to move water inside the housing, and a branch pipe that protrudes from a circumferential surface of the water outlet pipe and that is configured to move a part of water flowing through the water outlet pipe to the air jet generator. The control valve can be configured to control a flow of water to the branch pipe.

In some implementations, the dishwasher can include a connection pipe connecting the branch pipe to the air jet generator, where the control valve can be disposed at the connection pipe. In some examples, the pump can further include a heater configured to heat the water inside the housing, and a steam discharge pipe that protrudes from a circumferential surface of the water outlet pipe and that is configured to supply steam to the space of the tub. The branch pipe can protrude below the steam discharge pipe.

In some implementations, the control valve can be configured to, based on a main wash cycle of washing the target object using a detergent being completed, block the flow of the water to the air jet generator. In some implementations, the dishwasher can further include a connection pipe configured to move a part of the water discharged from the pump to the air jet generator. The control valve can be configured to, based on a main wash cycle of washing the target object using a detergent being completed, reduce an opening area of a flow path provided inside the connection pipe.

In some examples, the air jet generator can have a Venturi tube shape and can be configured to pulverize air introduced through an air inlet hole with water flowing through a flow path perpendicular to a bottom surface of the tub. In some implementations, the spray nozzle can be configured to spray water to the space.

In some implementations, the air jet generator can be configured to discharge the water having air bubbles to the space. In some implementations, the air jet generator can include an air crushing pipe including a first pipe providing (i) an inlet at a lower side of the air crushing pipe, (ii) an opening in a water flowing direction, and (iii) a cross-sectional area reducing in the water flowing direction, and a second pipe disposed above the first pipe, the second pipe providing (i) an opening in the water flowing direction and (ii) a cross-sectional area increasing in the water flowing direction, and an air tab disposed at an upper portion of the second pipe and vertically provided with a plurality of air holes.

In some examples, an air inlet hole can be provided at a first side of the air crushing pipe. In some examples, the air inlet hole can be provided at an upstream end of the second pipe.

In some implementations, the air inlet hole can be provided at a lower end of the second pipe. In some implementations, the air inlet hole can be provided perpendicularly to a direction of a flow path where the water flows into the second pipe.

In some implementations, the air jet generator can include an air chamber, and the air inlet hole can provide fluid communication between an inside of the air crushing pipe and an outside of the air crushing pipe through the air chamber. In some examples, the air inlet hole can be defined at a lower end of the air chamber. In some examples, the air chamber can define an external air inlet hole through which external air is introduced.

In some implementations, based on the pump being operated, the water can flow upwards from the first pipe towards the second pipe.

According to another aspect of the subject matter described in this application, a method for controlling a dishwasher can include receiving water by a sump, operating a pump to move the water in the sump to a space inside a tub disposed in the dishwasher, controlling a control valve so that a part of the water discharged from the pump is supplied to an air jet generator that is configured to generate air bubbles in the water, opening a dispenser to supply a detergent to the space, stopping the pump and operating a drain pump to drain the water from the sump, receiving water by the sump again, operating the pump to move the water in the sump to the space, and controlling the control valve to block the supply of the water discharged from the pump to the air jet generator.

According to another aspect of the subject matter described in this application, a method for controlling a dishwasher can include performing a main wash cycle of operating a pump and removing foreign substances from a target object to be washed placed inside a space of the dishwasher using a detergent, and performing a rinse cycle of operating the pump and washing the target object having undergone through the main wash cycle using water. In the main wash cycle, a control valve cam be controlled to cause a part of the water from the pump to move to an air jet generator that is configured to generate air bubbles, and, in the rinse cycle, the control valve can be controlled to block a part of the water from the pump from being introduced to the air jet generator.

The dishwasher can have following advantages.

First, the dishwasher can minimize noise occurring in the air jet generator by controlling water supplied to the air jet generator according to a washing step.

Second, as the branch pipe for supplying water to the air jet generator protrudes from the water outlet pipe downward compared to the steam discharge pipe in the dishwasher, the dishwasher can stably secure the flow rate of water flowing to the air jet generator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a schematic cross-sectional view of an exemplary dishwasher.

FIG. 2 is a diagram illustrating a perspective view of an exemplary air jet generator.

FIG. 3 is a diagram illustrating a cross-sectional perspective view of an exemplary air jet generator.

FIG. 4 is a diagram schematically illustrating an exemplary connection between a pump, an air jet generator, and a steam nozzle.

FIG. 5 is a diagram illustrating a perspective view of an exemplary pump.

FIG. 6 is a diagram illustrating a view for explaining an exemplary arrangement of a steam discharge pipe and a branch pipe disposed in a water outlet pipe.

FIG. 7A is a table showing noise occurring in an exemplary dishwasher in a state in which a control valve is operated according to a wash cycle.

FIG. 7B is a table showing noise occurring in the exemplary dishwasher in a state in which the control valve does not exist.

FIG. 8 is a flowchart illustrating a wash cycle of an exemplary dishwasher.

FIG. 9 is a flowchart illustrating a detailed method of controlling an exemplary dishwasher in a main wash cycle and a rinse cycle.

DETAILED DESCRIPTION

Referring to FIG. 1, a dishwasher 10 can include a cabinet 20 defining an external appearance of the dishwasher, a door 22 coupled to the cabinet 20 and configured to open and close the inside of the cabinet 20, and a tub 24 disposed inside the cabinet 20 and defining a space 24 s in which water or steam is applied.

The dishwasher 10 can include a dispenser that stores detergent received from a user and that sprays the detergent into the tub 24 in a wash cycle. The dispenser can be disposed at the door 22. In some implementations, the tub 24 defines the space 24 s in which the dishes are disposed for washing dishes.

The dishwasher 10 can further include racks 30 and 32 for accommodating dishes in the tub 24, a plurality of spray nozzles 34, 36, and 38 for spraying water toward the dishes accommodated in the racks 30 and 32, a sump 26 disposed below the tub 24 and configured to receive and store water, and a pump 50 for pressurizing the water stored in the sump 26 to move the water to the plurality of spray nozzles 34, 36, and 38.

The dishwasher 10 can further include a motor 58 for driving the pump 50, and a brushless direct current motor (BLDC) capable of controlling a rotational speed may be used as the motor 58.

The dishwasher 10 can further include a water supply device 70 for supplying water to the sump 26, a drain device 72 connected to the sump 26 to discharge water to the outside of the dishwasher, and a filter 78 installed in the sump 26 and filters water.

The dishwasher 10 can further include a plurality of supply tubes 42, 44, and 46 for moving water pumped by the pump 50 to each of the plurality of spray nozzles 34, 36, and 38, and a flow path switching part 40 for moving the water pumped by the pump 50 to at least one of the plurality of spray nozzles 34, 36, and 38.

The water supply device 70 can be configured to receive water from the outside of the dishwasher and supply the water to the sump 26, and opens and closes a water supply valve 71 a disposed on the water supply flow path 71 to supply external water into the sump 26. The drain device 72 can discharge the water stored in the sump 26 to the outside of the dishwasher, and can include a drain flow path 74 and a drain pump 76.

The filter 78 can filter out foreign substances such as food particles contained in the water, and can be disposed on a flow path of the water flowing from the tub 24 to the sump 26.

The dishwasher 10 can further includes the pump 50 for pressurizing the water stored in the sump 26 to move the water to the spray nozzles 34, 36, and 38. The pump 50 can includes a pump housing 51, a pump impeller 54 disposed in the pump housing 51 and rotating to supply water to the spray nozzles 34, 36, and 38, a motor 58 for rotating the pump impeller 54, and a heater 56 for heating the water inside the pump housing 51.

The pump 50 can be connected to the sump 26 through a water supply tube 60 and can be connected to the flow path switching part 40 through a water outlet pipe 62. A branch pipe 66 can be provided in the water outlet pipe 62, so that a part of the water flowing from the pump 50 can flow to an air jet generator 100 through the branch pipe 66.

Steam generated by the heater 56 disposed in the pump 50 can flow to a steam nozzle 48 through a steam discharge pipe 64, and can be supplied into the tub 24 through the steam nozzle 48.

The dishwasher can further include the air jet generator 100 that can generate micro air bubbles in the water.

In the dishwasher 10, a part of the water moved by the pump 50 is supplied to the air jet generator 100 in addition to the spray nozzles 34, 36, 38 through the branch pipe 66. In the air jet generator 100, the water can be supplied through a flow path branched from the pump 50 and air can be introduced into the supplied water, and the air jet generator 100 can crash or pulverize the introduced air to generate micro air bubbles. The air jet generator 100 can be connected to the tub 24 or the sump 26. In some implementations, when the pump is operated, the water with the air bubbles generated by the air jet generator 100 can be supplied into the sump 26, so the water pumped to the spray nozzles 34, 36, and 38 includes the air bubbles.

A bottom hole can be defined at a bottom of the tub 24 so that a portion of an upper side of the air jet generator 100 can pass the bottom hole. The upper side of an air crushing pipe 110 of the air jet generator 100 (see FIG. 2) can pass through the bottom hole. In some implementations, a portion of the upper side of the air crushing pipe 110 of the air jet generator 100 can be disposed above a bottom of the tub 24.

The water stored in the sump 26 of the dishwasher 10 can be supplied to the spray nozzles 34, 36, and 38 through the pump 50, and the water supplied to the spray nozzles 34, 36, and 38 can be sprayed into the tub 24, and the water sprayed into the tub 24 can be introduced to the sump 26 again. In some implementations, a part of the water pumped from the pump 50 can be introduced into the air jet generator 100 that generates air bubbles in the water. A part of the water flowing by the pump 50 can flow to the air jet generator 100 through the branch pipe 66.

A part of the water discharged from the pump 50 can be supplied to the air jet generator 100. The air jet generator 100 can move the introduced water to pass through an impeller 170, an air inlet hole 150, an air crushing pipe 110 including a first tube 120 and a second tube 130, and an air tab 180 so as to generate air bubbles in the water (see FIG. 3). For example, the water introduced into the air jet generator 100 can spirally flow by the impeller 170. Thereafter, the water can increase in speed while passing through the first tube 120, and the air introduced into the air inlet hole can be primarily crushed or pulverized by the water rotating at a high speed by the impeller 170 and the first tube 120. In addition, the water can be secondarily crushed or pulverized while passing through the second tube 130. In addition, as the water is tertiarily crushed while passing through the air tab 180, micro air bubbles can be included in the water.

The water including the air bubbles can be introduced into the sump 26 again. The water including the air bubbles can be discharged through the tub 24 and introduced into the sump 26. Therefore, when the pump 50 is operated upon the operation of the dishwasher 10, air bubbles can be generated in the water.

Hereinafter, the configuration and arrangement of the air jet generator will be described with reference to FIGS. 2 to 6.

The air jet generator 100 can be disposed at a bottom surface 25 of the tub 24. The air jet generator 100 can be disposed at an edge of the bottom surface 25 of the tub 24.

A mounting hole through which a part of the air jet generator 100 passes through can be defined at the bottom surface 25 of the tub 24 at a portion where the air jet generator 100 is mounted.

Referring to FIGS. 2 to 3, the air jet generator 100 can include the air crushing pipe 110 that provides a flow path perpendicular to the bottom surface 25 of the tub 24 or the ground and that has the shape of a Venturi tube, and has the air inlet hole 150 defined at one side of the air crushing pipe 110 to introduce external air, an air tab 180 that is configured to crush or pulverize air contained in the water discharged from the air crushing tube, and an air chamber 152 that is disposed at an outer side of the air crushing tube, that defines a space through which air flows, and that has an air inlet hole defined at one side of the bottom of the air chamber 152 to provide fluid communication with the inside of the air crushing tube. In some implementations, the air jet generator 100 can further include the impeller 170 that applies a centrifugal force to the water flowing into the air crushing tube.

Referring to FIGS. 2 to 3, the dishwasher 10 can have a connection pipe 68 that moves a part of the water flowing from the pump 50 to the spray nozzles 34, 36, 38 to the air jet generator 100. An end of the connecting pipe 68 can be coupled to a lower portion of the air crushing pipe 110. The connecting pipe 68 and the air crushing pipe 110 can be coupled by fusion bonding.

The connection pipe 68 can move a part of the water flowing through the water outlet pipe 62 to the air jet generator 100. For example, the connection pipe 68 can be branched from the water outlet pipe 62 and can be connected to the air jet generator 100.

The impeller 170 can be configured to apply a centrifugal force to the water flowing into the air crushing pipe 110 and can be disposed at an end of the connection pipe 68. The impeller 170 can be mounted inside one side of the connection pipe 68. The impeller 170 can be coupled to the inside of the connection pipe 68 by fusion bonding.

Referring to FIG. 3, the impeller 170 can include a cylindrical outer wall 172 and a vane 174 disposed within the outer wall 172 to form a swirl flow in the water. The water passing through the impeller 170 can pass through the vane 174 and can thereby be rotated to cause a swirling flow.

The vane 174 of the impeller 170 can apply centrifugal force to the water flowing into the first tube 120. The vane 174 of the impeller 170 can be fixed or rotatable, and the water passing through the vane 174 can be swirled and introduced into the air crushing pipe 110.

Referring to FIG. 3, the air crushing pipe 110 can have a Venturi tube shape. The air crushing pipe 110 can crush or pulverize air introduced into the air inlet hole 150 with the water flowing therein.

The air crushing pipe 110 can include the first tube 120 in which the cross-sectional area of a flow path decreases in a flow direction of the water to depressurize the water flowing therein, and the second tube 130 in which the cross-sectional area of a flow path increases in a flow direction of the water to pressurize the water containing air. The first tube 120 and the second tube 130 can each provide a flow path opened in a vertical direction. The first tube 120 can be disposed at the upstream of the second tube 130. The first tube 120 can be disposed at a position lower than that of the second tube 130.

The air inlet hole 150 for introducing external air into the air crushing pipe 110 by applying negative pressure occurring in the tube can be defined at a circumferential surface of a lower end of the second tube 130. The air inlet hole 150 can be defined at an upstream end of the second tube 130.

The air crushing pipe 110 can be disposed below the bottom surface 25 of the tub 24. The air crushing pipe 110 can be disposed to be perpendicular to the ground or the bottom surface 25 of the tub 24.

Referring to FIG. 3, in the air crushing pipe 110, the first tube 120 and the second tube 130 can be disposed in order in a direction in which the water flows.

Referring to FIG. 3, the air tab 180 can be mounted at a discharge end of the air crushing pipe 110 from which the water is discharged. The air tab 180 can be disposed above the air crushing pipe 110.

Referring to FIG. 3, the second tube 130 can be disposed above the first tube 120. The second tube 130 can be disposed at the downstream of the first tube 120. In the second tube 130, the cross-sectional area of the flow path of increases in the flow direction of the water, thereby pressurizing the water. As the water flowing along the second tube 130 is pressurized, the air introduced into the air crushing pipe 110 through the air inlet hole 150 can be secondarily crushed.

The second tube 130 can be longer than the first tube 120. The second tube 130 can be divided into a second tube lower part 132 for primarily pressurizing the water introduced from the first tube and a second tube upper part 134 for secondarily pressurizing the water passing through the second tube lower part 132. The second tube lower part 132 can pressurize the water gradually compared to the second tube upper part 134. The second tube lower part 132 can have a smaller rate of change of the flow path cross-sectional area than that of the second tube upper part 134.

For example, referring to FIG. 3, a flow path length formed in the vertical direction of the second tube lower part 132 is longer than a flow path length of the second tube upper part 134. A difference in inner diameter between both ends of the second tube lower part 132 in the vertical direction can be less than a difference in inner diameter between both ends of the second tube upper part 134 in the vertical direction.

In the second tube lower part 132, the air introduced into the air inlet hole 150 can be crushed or pulverized by the flow velocity of the water and the centrifugal force. The second tube upper part 134 can pressurize the water due to the rapid expansion of the flow path cross-sectional area, so that the air contained in the water can be effectively crushed.

The air inlet hole 150 can be defined at an upstream end of the second tube 130. The air inlet hole 150 can be defined at a lower end 132 a of the second tube 130.

Referring to FIG. 3, the air inlet hole 150 can be defined between the first tube 120 and the second tube 130. The air inlet hole 150 can be defined at a portion where the flow path cross-sectional area of the first tube 120 is reduced. The air inlet hole 150 can be defined at an upstream end of the second tube 130. The air inlet hole 150 can be defined at a point where depressurization by the first tube 120 ends. The air inlet hole 150 can be defined at a point where pressurization by the second tube 130 starts.

The air inlet hole 150 can provide fluid communication between the inside of the air crushing pipe 110 and the outside of the air crushing pipe 110 through the air chamber 152. In the air crushing pipe 110, external air may be introduced into the air crushing pipe 110 through the air inlet hole 150. For example, the term “external air” may refer to the external air of the air crushing tube. Accordingly, “external air” may include internal air of a cabinet 20 or internal air of a tub 24.

The water flowing through the air crushing pipe 110 can be depressurized while passing through the first tube 120. Since negative pressure is formed due to the depressurization of the water passing through the first tube, external air can be suctioned into the air crushing pipe 110 through the air inlet hole 150. The air introduced into the air crushing pipe 110 through the air inlet 150 hole can be primarily crushed or pulverized by a swirl flow of water flowing at a high speed along the first tube 120.

Referring to FIG. 3, the air chamber 152 for reducing noise occurring in the air crushing pipe 110 can be disposed at one side of the air crushing pipe 110. The air chamber 152 can reduce noise that propagates to the outside through the air inlet hole 150.

The air chamber 152 can provide a space in which noise propagates. The air chamber 152 can be disposed at the outside of the air crushing pipe 110 in which the air inlet hole 150 is defined. The air inlet hole 150 that is in fluid communication with the inside of the air crushing pipe 110 is defined at one side of the lower end of the air chamber 152.

Referring to FIG. 3, the air inlet hole 150 can be defined at a lower end of the air chamber 152. Therefore, even if the water flows into the air chamber 152, the water may not be allowed to flow to the air inlet hole 150 defined at the lower end of the air chamber 152, so that the water is not pooled in the air chamber 152. In the air chamber 152, an external air inlet hole 154 through which external air is introduced into the air chamber 152 can be defined. The external air inlet hole 154 can be defined at an upper end of the air chamber 152. Therefore, the water introduced into the air chamber 152 can be blocked from escaping to the outside of the air chamber 152.

The air chamber 152 can be disposed at an outside of the air crushing pipe 110 in which the air inlet hole 150 is defined.

Referring to FIG. 3, the air crushing pipe 110 can include a tub mounting part that is coupled to the bottom surface 25 of the tub 24. The tub mounting part can be defined at an outer circumference of the air crushing pipe 110 at an upper side of the second tube 130. The tub mounting part can include a lower fixing plate 138 protruding in a circumferential direction from an outer circumferential surface of the air crushing pipe 110, and a upper fixing part 140 protruding upward from the bottom surface of the tub 24 and coupled to a fixing ring 190.

The bottom surface of the tub 24 can be disposed between the lower fixing plate 138 and the fixing ring 190 coupled to the upper fixing part 140. The upper fixing part 140 can be combined with the fixing ring 190 to reduce downward movement of the air crushing pipe 110.

The fixing ring 190 can have a ring shape and can be coupled to the upper fixing part 140 of the air crushing pipe 110. An inner circumferential surface of the fixing ring 190 can provide a thread corresponding to the upper fixing part 140.

The bottom surface 25 of the tub 24 can be disposed between the lower fixing plate 138 and the fixing ring 190 of the air crushing pipe 110. A sealer for reducing leakage of the water flowing on the bottom surface 25 of the tub 24 from leaking downward can be disposed between the lower fixing plate 138 of the air crushing pipe 110 and the fixing ring 190. The sealer can be disposed below and/or above the bottom surface 25 of the tub 24.

The air tab 180 can have a disk shape, and a plurality of holes 182 penetrating the air tab 180 can be provided. The water passing through the second tube 130 can pass through the air tab 180. Air in the water can be tertiarily crushed while passing through the plurality of holes 182 provided in the air tab 180.

The larger the contact area with the air bubbles, the greater the shear force can be applied to the air bubbles, which can increase the amount of air bubbles. Thus, the holes 182 provided in the air tab 180 can be a long hole type compared to a through hole type.

A nozzle 200 can be disposed above the air crushing pipe 110. The nozzle 200 can be disposed above the air jet generator 100 and configured to discharge the water passing through the air jet generator 100 into the tub 24. The nozzle 200 can be disposed above the air tab 180. The nozzle 200 can be coupled to the air tab 180 by fusion bonding.

Referring to FIGS. 2 and 3, in the nozzle 200, a plurality of discharge holes 204 can be defined above the inlet hole 206 in a downward direction from a radially outer side of the inlet hole 206.

Referring to FIG. 2, the plurality of discharge holes 204 can be spaced apart from each other by a predetermined distance along a circumferential surface of the nozzle 200. As the nozzle 200 has the plurality of discharge holes 204 defined along the circumferential surface, water containing air bubbles can be discharged to the bottom surface 25 of the tub 24 in various directions.

In the air jet generator 100, a flow path through which the water flows can be disposed perpendicular to the ground or the bottom surface of the tub 24. Therefore, an area in which the water flowing through the second tube 130 does not flow due to the rapid expansion of the flow path in the second tube upper part 134 can be minimized.

Referring to FIG. 4, the pump 50 can include the pump housing 51, the water supply tube 60 protruding outward from a circumferential surface of the pump housing 51, and the water outlet pipe 62. The steam discharge pipe 64 for supplying steam to the steam nozzle 48 and the branch pipe 66 for supplying a part of water to the air jet generator 100 can protrude from the circumferential surface of the water outlet pipe 62.

Referring to FIG. 4, a control valve 69 that provides or blocks a flow of water flowing from the pump 50 to the air jet generator 100 can be disposed in the branch pipe 66. The branch pipe 66 and the air jet generator 100 can be connected to the connection pipe 68. The control valve 69 can be disposed at the connection pipe 68 to open and close a flow path provided in the connection pipe 68.

A solenoid valve can be used for the control valve 69. Therefore, the inside of the connection pipe 68 can be closed or opened according to a current signal. When the solenoid valve is used, the control valve 69 can be controlled to open or close the inside of the connection pipe 68 according to a cycle of the dishwasher.

A flow control valve for controlling an opening area of the flow path provided in the connection pipe 68 can also be used as the control valve 69. Therefore, when the flow control valve is used, the control valve 69 can control the opening area of the inside of the connection pipe 68 according to a cycle of the dishwasher.

The steam discharge pipe 64 can protrude upward from the circumferential surface of the water outlet pipe 62. A direction in which the branch pipe 66 extends from the water outlet pipe 62 can be disposed to be downward compared to a direction in which the steam discharge pipe 64 extends from the water outlet pipe 62. Referring to FIGS. 5 to 6, the steam discharge pipe 64 can be connected to the water outlet pipe 62 at a higher position compared to the branch pipe 66.

Referring to FIG. 8, the dishwasher can wash dishes while sequentially or selectively performing a preliminary wash cycle S100, a main wash cycle S200, a rinse cycle S300, and a dry cycle S400.

The entire operation of the dishwasher will be described briefly as follows. The preliminary wash cycle S100 is a step of removing foreign substances mainly of protein with water at room temperature without heating the water, and water supply, washing, and drainage can be performed in the preliminary wash cycle S100.

The main wash cycle S200 is a step of removing foreign substances remaining on dishes and the like using dishwashing detergent, and water supply, washing, and drainage can be performed in the main wash cycle S200. In the main wash cycle S200, water can be heated by a heater to remove foreign substances. In addition, in the process of the main wash cycle S200, steam can be supplied into the space 24 s through the steam nozzle 48. In the process of the main wash cycle S200, the dispenser can be opened to put detergent into the space 24 s.

The rinse cycle S300 is a step of washing dishes having undergone through the main wash cycle using water, and water supply, rinsing, and drainage can be performed. An operation of heating water may be added in the rinse cycle.

The dry cycle S400 is a step of removing water from dishes that have been washed and rinsed, and water remaining on the dishes can be removed using air heated by a heater in the dry cycle S400.

The control valve 69 can open the connection pipe 68 so that the water flows to the air jet generator 100 in the main wash cycle S200. For example, in the preliminary wash cycle S100 or the rinse cycle S300, the control valve 69 can close the flow path inside the connection pipe 68.

When the water is supplied to the air jet generator 100, noise may be transferred to the outside of the dishwasher as the introduced air is crushed. Therefore, by reducing an operating time of the air jet generator 100, the transfer of the noise to the outside can be reduced. In the case of the main wash cycle, when water including air bubbles is supplied toward dishes, food particles on the dishes can be effectively removed. Therefore, in the main wash cycle S200, the control valve 69 can open the connection pipe 68 so that the water is supplied to the air jet generator 100.

Referring to FIG. 7A, in the entire cycles, it may be understood that noise of about 50 dB is generated even in the preliminary wash cycle S100 or the rinse cycle S300 when water is supplied to the air jet generator 100. However, referring to FIG. 7B, it may be understood that the noise is at approximately 45 dB in the preliminary wash cycle S100 or the rinse cycle S300, which indicates the reduction of the noise by about 10%.

However, in the rinse cycle S300, the control valve 69 can be controlled to block the water supplied to the air jet generator 100. In this case, noise occurring in the rinse cycle can be reduced. Similarly, in the preliminary wash cycle S100, the control valve 69 can be controlled to block the water supplied to the air jet generator 100.

In addition, in the rinse cycle S300 and the preliminary wash cycle S100, the control valve 69 can also be controlled to reduce the area of the flow path formed in the connection pipe 68. When the flow rate of the water flowing to the air jet generator 100 decreases, the amount of air introduced into the air jet generator 100 can also decrease, thereby reducing noise.

Referring to FIG. 9, the main wash cycle S200 and the rinse cycle S300 will be described in detail.

First, an operation S210 of supplying water to the sump 26 is performed. The water can be supplied to the sump 26 from an external water source.

An operation S220 of operating the pump 50 so that the water is supplied to the space 24 s through the spray nozzles 34, 36, and 38 can be performed. In addition, an operation S230 of controlling the control valve 69 so that the connection pipe 68 or the branch pipe 66 connecting the pump 50 and the air jet generator 100 is opened can be performed. The operation S220 of operating the pump 50 and the operation S230 of controlling the control valve 69 can be performed simultaneously or sequentially, and the order of the operations S220 and S230 can be changed.

A part of the water supplied from the pump 50 flows to the air jet generator 100 and is then supplied to the space 24 s. As the water circulates, the air bubbles generated by the air jet generator 100 can be supplied to the dishes through the spray nozzles 34, 36, and 38.

In addition, an operation of S240 of opening the dispenser to supply detergent into the space 24 s can be performed.

Thereafter, the operation of the pump 50 can be stopped in operation S250, and the drain pump 76 can operate to discharge the water inside the sump 26 in operation S260. Then, as the drain pump 76 can be stopped in operation S270, the main wash cycle S200 can be finished.

Then, an operation S310 of re-supplying water to the sump 26 can be performed.

An operation S320 of operating the pump 50 to supply the water to the space 24 s through the spray nozzles 34, 36, and 38 can be performed. In addition, an operation S330 of controlling the control valve 69 to close the connection pipe 68 or the branch pipe 66 can be performed. The operation S320 of operating the pump 50 and the operation S330 of controlling the control valve 69 can be performed simultaneously or sequentially, and the order of the operations S320 and S330 can be changed.

In this case, even when the pump 50 is operated, the water does not flow to the air jet generator 100, and thus, no noise is generated in the air jet generator 100.

Then, the pump 50 is stopped in operation S340, and the drain pump 76 is operated in operation S350 to drain the water in the sump 26. When the drainage is completed, the drain pump 76 can be stopped in operation S360. 

What is claimed is:
 1. A dishwasher comprising: a tub defining a space that is configured to receive a target object to be washed; a sump disposed below the tub and configured to receive water; a pump connected to the sump and configured to move the water in the sump to the space of the tub; an air jet generator configured to receive a part of the water discharged from the pump and configured generate air bubbles in the water; and a control valve configured to control a flow of the water to the air jet generator.
 2. The dishwasher of claim 1, wherein the pump comprises: a housing, a water inlet pipe that protrudes from a first side of a circumferential surface of the housing and that is connected to the sump, a water outlet pipe that protrudes from the first side of the circumferential surface of the housing and that is connected to a spray nozzle disposed inside the space, an impeller rotatably disposed inside the housing and configured to move water inside the housing, and a branch pipe that protrudes from a circumferential surface of the water outlet pipe and that is configured to move a part of water flowing through the water outlet pipe to the air jet generator, wherein the control valve is configured to control a flow of water to the branch pipe.
 3. The dishwasher of claim 2, further comprising: a connection pipe connecting the branch pipe to the air jet generator, wherein the control valve is disposed at the connection pipe.
 4. The dishwasher of claim 2, wherein the pump further comprises: a heater configured to heat the water inside the housing, and a steam discharge pipe that protrudes from a circumferential surface of the water outlet pipe and that is configured to supply steam to the space of the tub, wherein the branch pipe protrudes below the steam discharge pipe.
 5. The dishwasher of claim 1, wherein the control valve is configured to, based on a main wash cycle of washing the target object using a detergent being completed, block the flow of the water to the air jet generator.
 6. The dishwasher of claim 1, further comprising: a connection pipe configured to move a part of the water discharged from the pump to the air jet generator, wherein the control valve is configured to, based on a main wash cycle of washing the target object using a detergent being completed, reduce an opening area of a flow path provided inside the connection pipe.
 7. The dishwasher of claim 6, wherein the air jet generator has a Venturi tube shape and is configured to pulverize air introduced through an air inlet hole with water flowing through a flow path perpendicular to a bottom surface of the tub.
 8. The dishwasher of claim 2, wherein the spray nozzle is configured to spray water to the space.
 9. The dishwasher of claim 1, wherein the air jet generator is configured to discharge the water having air bubbles to the space.
 10. The dishwasher of claim 1, wherein the air jet generator includes: an air crushing pipe including a first pipe providing (i) an inlet at a lower side of the air crushing pipe, (ii) an opening in a water flowing direction, and (iii) a cross-sectional area reducing in the water flowing direction, and a second pipe disposed above the first pipe, the second pipe providing (i) an opening in the water flowing direction and (ii) a cross-sectional area increasing in the water flowing direction, and an air tab disposed at an upper portion of the second pipe and vertically provided with a plurality of air holes.
 11. The dishwasher of claim 10, wherein an air inlet hole is provided at a first side of the air crushing pipe.
 12. The dishwasher of claim 11, wherein the air inlet hole is provided at an upstream end of the second pipe.
 13. The dishwasher of claim 11, wherein the air inlet hole is provided at a lower end of the second pipe.
 14. The dishwasher of claim 11, wherein the air inlet hole is provided perpendicularly to a direction of a flow path where the water flows into the second pipe.
 15. The dishwasher of claim 11, wherein the air jet generator includes an air chamber, and wherein the air inlet hole provides fluid communication between an inside of the air crushing pipe and an outside of the air crushing pipe through the air chamber.
 16. The dishwasher of claim 15, wherein the air inlet hole is defined at a lower end of the air chamber.
 17. The dishwasher of claim 15, wherein the air chamber defines an external air inlet hole through which external air is introduced.
 18. The dishwasher of claim 10, wherein, based on the pump being operated, the water flows upwards from the first pipe towards the second pipe.
 19. A method for controlling a dishwasher, the method comprising: receiving water by a sump; operating a pump to move the water in the sump to a space inside a tub disposed in the dishwasher; controlling a control valve so that a part of the water discharged from the pump is supplied to an air jet generator that is configured to generate air bubbles in the water; opening a dispenser to supply a detergent to the space; stopping the pump and operating a drain pump to drain the water from the sump; receiving water by the sump again; operating the pump to move the water in the sump to the space; and controlling the control valve to block the supply of the water discharged from the pump to the air jet generator.
 20. A method for controlling a dishwasher, the method comprising: performing a main wash cycle of operating a pump and removing foreign substances from a target object to be washed placed inside a space of the dishwasher using a detergent; and performing a rinse cycle of operating the pump and washing the target object having undergone through the main wash cycle using water, wherein, in the main wash cycle, a control valve is controlled to cause a part of the water from the pump to move to an air jet generator that is configured to generate air bubbles, wherein, in the rinse cycle, the control valve is controlled to block a part of the water from the pump from being introduced to the air jet generator. 